POS0083 A SYSTEMATIC LITERATURE REVIEW INFORMING THE EULAR RECOMMENDATIONS FOR THE USE OF IMAGING IN CRYSTAL-INDUCED ARTHRITIS IN CLINICAL PRACTICE
Authors: I. Gessl, G. Sakellariou, G. Filippou, P. Mandl, B. Wildner, M. A. D’agostino, V. Navarro-Compán
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> The increased availability of imaging techniques has led to their more extensive use in rheumatological practice. In the context of crystal-induced arthritis (CiA), evidence-based recommendations for their use are lacking. <h3>Objectives</h3> To systematically assess current literature regarding the use of imaging in CiA. <h3>Methods</h3> After the identification of the areas of interest and 14 research questions for the application of imaging in CiA, we performed 4 separate systematic literature searches (per disease and per indication) in Embase, Medline, and Central regarding the use of imaging for the diagnosis, monitoring and prediction of outcome and treatment effects of gout, calcium pyrophosphate dihydrate crystal deposition disease (CPPD) and basic calcium phosphate/hydroxyapatite crystal deposition disease (BCPD), as well as for guiding intra-articular procedures and patient education. Titles and abstracts were screened, the full-text of the eligible articles were reviewed and data of the included studies were extracted. Risk of bias was assessed validated instruments based on study type. <h3>Results</h3> The overview of the included studies for each research question and imaging modality is shown in Table 1. For gout, out of 2915 studies, 88 studies were finally included (table 1, figure 1). The majority of diagnostic studies reported good to excellent (≥80%) sensitivity and specificity of DECT and US for diagnosis. Conventional radiographs (CR) and computed tomography (CT) showed high specificity but lower sensitivity in most studies. The majority of the follow-up studies showed a significant change of crystal deposition by US and DECT and inflammatory signs by US. An increase of structural damage was shown in some studies by CR and CT, mainly after a follow-up of at least 2 years. For CPPD, out of 687 studies, 50 studies were included (table 1, figure 1). Diagnostic studies on CR and US generally showed high specificity in all joints, in particular wrists and knees, while sensitivity was more variable, but generally high. There was a single study on monitoring, while 9 studies assessed the prognostic role of CPPD on CR and MRI in patients with OA, with contradicting results. Evidence on the application of DECT was scarce. For BCPD/HADD, out of 1389 abstracts, 55 studies were included (table 1, figure 1). There were 2 diagnostic studies, one on CR, reporting good performance, and one on MRI, with suboptimal performance. The utility of imaging in monitoring was assessed in 43 studies, mostly on CR and US of the shoulder, the majority reporting a reduction in the size of deposits, while 12 studies with contrasting results assessed the role of CR, US and MRI for prediction of treatment response. The search on patient education retrieved 254 studies, of which 2 could be included, which suggest a potential role of DECT in patient education. No studies on the role of imaging to guide procedures in CiA could be included in the final review (table 1, figure 1). <h3>Conclusion</h3> The present SLR has provided background evidence for the development of EULAR recommendations on the use of imaging in CiA in clinical practice. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.